335 lines
9.4 KiB
C++
335 lines
9.4 KiB
C++
/*
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Softserial for Nextion LCD and Control MCU
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KD8CEC, Ian Lee
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-----------------------------------------------------------------------
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It is a library rewritten in C format based on SoftwareSerial.c.
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I tried to use as much as possible without modifying the SoftwareSerial.
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But eventually I had to modify the code.
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I rewrote it in C for the following reasons.
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- Problems occurred when increasing Program Size and Program Memory
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- We had to reduce the program size.
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Of course, Software Serial is limited to one.
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- reduce the steps for transmitting and receiving
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useage
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extern void SWSerial_Begin(long speedBaud);
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extern void SWSerial_Write(uint8_t b);
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extern int SWSerial_Available(void);
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extern int SWSerial_Read(void);
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extern void SWSerial_Print(uint8_t *b);
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If you use Softwreserial library instead of this library, you can modify the code as shown below.
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I kept the function name of SoftwareSerial so you only need to modify a few lines of code.
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define top of source code
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#include <SoftwareSerial.h>
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SoftwareSerial sSerial(10, 11); // RX, TX
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replace source code
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SWSerial_Begin to sSerial.begin
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SWSerial_Write to sSerial.write
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SWSerial_Available to sSerial.available
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SWSerial_Read to sSerial.read
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KD8CEC, Ian Lee
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-----------------------------------------------------------------------
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License
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All licenses for the source code are subject to the license of the original source SoftwareSerial Library.
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However, if you use or modify this code, please keep the all comments in this source code.
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KD8CEC
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-----------------------------------------------------------------------
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License from SoftwareSerial
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-----------------------------------------------------------------------
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SoftwareSerial.cpp (formerly NewSoftSerial.cpp) -
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Multi-instance software serial library for Arduino/Wiring
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-- Interrupt-driven receive and other improvements by ladyada
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(http://ladyada.net)
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-- Tuning, circular buffer, derivation from class Print/Stream,
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multi-instance support, porting to 8MHz processors,
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various optimizations, PROGMEM delay tables, inverse logic and
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direct port writing by Mikal Hart (http://www.arduiniana.org)
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-- Pin change interrupt macros by Paul Stoffregen (http://www.pjrc.com)
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-- 20MHz processor support by Garrett Mace (http://www.macetech.com)
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-- ATmega1280/2560 support by Brett Hagman (http://www.roguerobotics.com/)
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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The latest version of this library can always be found at
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http://arduiniana.org.
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*/
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#include <arduino.h>
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//================================================================
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//Public Variable
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//================================================================
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#define TX_PIN 9
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#define RX_PIN 8
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#define _SS_MAX_RX_BUFF 35 // RX buffer size
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#define PRINT_MAX_LENGTH 30
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//================================================================
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//Internal Variable from SoftwareSerial.c and SoftwareSerial.h
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//================================================================
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//variable from softwareserial.c and softwareserial.h
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static uint8_t swr_receive_buffer[_SS_MAX_RX_BUFF];
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volatile uint8_t *_transmitPortRegister; //Write Port Register
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uint8_t transmit_RegMask; //use Mask bit 1
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uint8_t transmit_InvMask; //use mask bit 0
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volatile uint8_t *_receivePortRegister; //Read Port Register
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uint8_t _receiveBitMask;
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//delay value for Bit
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uint16_t _tx_delay;
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//delay value for Receive
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uint16_t _rx_delay_stopbit;
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uint16_t _rx_delay_centering;
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uint16_t _rx_delay_intrabit;
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//Customize for uBITX Protocol
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int8_t receiveIndex = 0;
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uint8_t receivedCommandLength = 0;
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int8_t ffCount = 0;
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//Values for Receive Buffer
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//uint16_t _buffer_overflow;
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//static volatile uint8_t _receive_buffer_head;
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//static volatile uint8_t _receive_buffer_tail;
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//Values for Interrupt (check Start Bit)
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volatile uint8_t *_pcint_maskreg;
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uint8_t _pcint_maskvalue;
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//================================================================
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//Internal Function from SoftwareSerial.c
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//================================================================
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uint16_t subtract_cap(uint16_t num, uint16_t sub)
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{
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if (num > sub)
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return num - sub;
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else
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return 1;
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}
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inline void tunedDelay(uint16_t delay)
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{
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_delay_loop_2(delay);
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}
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void setRxIntMsk(bool enable)
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{
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if (enable)
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*_pcint_maskreg |= _pcint_maskvalue;
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else
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*_pcint_maskreg &= ~_pcint_maskvalue;
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}
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uint8_t rx_pin_read()
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{
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return *_receivePortRegister & _receiveBitMask;
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}
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//
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// The receive routine called by the interrupt handler
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//
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void softSerail_Recv()
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{
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#if GCC_VERSION < 40302
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// Work-around for avr-gcc 4.3.0 OSX version bug
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// Preserve the registers that the compiler misses
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// (courtesy of Arduino forum user *etracer*)
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asm volatile(
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"push r18 \n\t"
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"push r19 \n\t"
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"push r20 \n\t"
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"push r21 \n\t"
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"push r22 \n\t"
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"push r23 \n\t"
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"push r26 \n\t"
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"push r27 \n\t"
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::);
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#endif
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uint8_t d = 0;
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// If RX line is high, then we don't see any start bit
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// so interrupt is probably not for us
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if (!rx_pin_read()) //Start Bit
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{
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// Disable further interrupts during reception, this prevents
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// triggering another interrupt directly after we return, which can
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// cause problems at higher baudrates.
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setRxIntMsk(false);
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// Wait approximately 1/2 of a bit width to "center" the sample
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tunedDelay(_rx_delay_centering);
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// Read each of the 8 bits
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for (uint8_t i=8; i > 0; --i)
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{
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tunedDelay(_rx_delay_intrabit);
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d >>= 1;
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if (rx_pin_read())
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d |= 0x80;
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}
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if (receivedCommandLength == 0) //check Already Command
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{
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//Set Received Data
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swr_receive_buffer[receiveIndex++] = d;
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//Finded Command
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if (d == 0x73 && ffCount > 1 && receiveIndex > 6)
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{
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receivedCommandLength = receiveIndex;
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receiveIndex = 0;
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ffCount = 0;
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}
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else if (receiveIndex > _SS_MAX_RX_BUFF)
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{
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//Buffer Overflow
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receiveIndex = 0;
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ffCount = 0;
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}
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else if (d == 0xFF)
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{
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ffCount++;
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}
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else
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{
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ffCount = 0;
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}
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}
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// skip the stop bit
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tunedDelay(_rx_delay_stopbit);
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// Re-enable interrupts when we're sure to be inside the stop bit
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setRxIntMsk(true);
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}
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#if GCC_VERSION < 40302
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// Work-around for avr-gcc 4.3.0 OSX version bug
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// Restore the registers that the compiler misses
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asm volatile(
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"pop r27 \n\t"
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"pop r26 \n\t"
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"pop r23 \n\t"
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"pop r22 \n\t"
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"pop r21 \n\t"
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"pop r20 \n\t"
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"pop r19 \n\t"
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"pop r18 \n\t"
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::);
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#endif
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}
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ISR(PCINT0_vect)
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{
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softSerail_Recv();
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}
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//================================================================
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//Public Function from SoftwareSerial.c and modified and create
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//================================================================
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// Read data from buffer
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void SWSerial_Read(uint8_t * receive_cmdBuffer)
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{
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for (int i = 0; i < receivedCommandLength; i++)
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receive_cmdBuffer[i] = swr_receive_buffer[i];
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}
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void SWSerial_Write(uint8_t b)
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{
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volatile uint8_t *reg = _transmitPortRegister;
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uint8_t oldSREG = SREG;
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uint16_t delay = _tx_delay;
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cli(); // turn off interrupts for a clean txmit
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// Write the start bit
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*reg &= transmit_InvMask;
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tunedDelay(delay);
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// Write each of the 8 bits
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for (uint8_t i = 8; i > 0; --i)
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{
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if (b & 1) // choose bit
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*reg |= transmit_RegMask; // send 1
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else
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*reg &= transmit_InvMask; // send 0
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tunedDelay(delay);
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b >>= 1;
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}
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// restore pin to natural state
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*reg |= transmit_RegMask;
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SREG = oldSREG; // turn interrupts back on
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tunedDelay(_tx_delay);
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}
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void SWSerial_Print(uint8_t *b)
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{
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for (int i = 0; i < PRINT_MAX_LENGTH; i++)
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{
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if (b[i] == 0x00)
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break;
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else
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SWSerial_Write(b[i]);
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}
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}
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void SWSerial_Begin(long speedBaud)
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{
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//INT TX_PIN
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digitalWrite(TX_PIN, HIGH);
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pinMode(TX_PIN, OUTPUT);
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transmit_RegMask = digitalPinToBitMask(TX_PIN); //use Bit 1
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transmit_InvMask = ~digitalPinToBitMask(TX_PIN); //use Bit 0
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_transmitPortRegister = portOutputRegister(digitalPinToPort(TX_PIN));
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//INIT RX_PIN
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pinMode(RX_PIN, INPUT);
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digitalWrite(RX_PIN, HIGH); // pullup for normal logic!
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_receiveBitMask = digitalPinToBitMask(RX_PIN);
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_receivePortRegister = portInputRegister(digitalPinToPort(RX_PIN));
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//Set Values
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uint16_t bit_delay = (F_CPU / speedBaud) / 4;
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_tx_delay = subtract_cap(bit_delay, 15 / 4);
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if (digitalPinToPCICR(RX_PIN))
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{
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_rx_delay_centering = subtract_cap(bit_delay / 2, (4 + 4 + 75 + 17 - 23) / 4);
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_rx_delay_intrabit = subtract_cap(bit_delay, 23 / 4);
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_rx_delay_stopbit = subtract_cap(bit_delay * 3 / 4, (37 + 11) / 4);
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*digitalPinToPCICR(RX_PIN) |= _BV(digitalPinToPCICRbit(RX_PIN));
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_pcint_maskreg = digitalPinToPCMSK(RX_PIN);
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_pcint_maskvalue = _BV(digitalPinToPCMSKbit(RX_PIN));
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tunedDelay(_tx_delay); // if we were low this establishes the end
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}
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//Start Listen
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setRxIntMsk(true);
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}
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